Means for controlling a fuel injection pump for an internal combustion engine



n 1 5 F. M. EVANS 2,839,287

MEANS FOR CONTROLLING A FUEL INJECTION PUMP FOR AN INTERNAL COMBUSTION ENGINE Filed March 25, 1955 Fig.1 k

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I h k \\\V lu P United States Patent MEANS FOR CONTROLLING A FUEL INJECTION PUMP FOR AN INTERNAL COMBUSTION EN- GINE Fraser Mackie Evans, Acton, London, England, assignor to C. A. V. Limited, London, England Application March 25, 1955, Serial No. 496,871

Claims priority, application Great Britain March 29, 1954 1 Claim. 01. 264-3) This invention relates to liquid fuel injection pumps for use on internal combustion engines, the pumps being of the kind in which the output under varying speed conditions is effected by a slidable control bar connected to a centrifugal governor, the latter being connected to the bar by a lever which is pivoted on a manually operable lever adapted to determine the speed at which the governor becomes operative, a plurality of two or more stops being provided to serve as abutments for corresponding projections on the governor-actuated lever and so arranged that while the engine speed is less than a predetermined rate the lever co-operates with one of the stops, and at a higher rate it co-operates with another of the stops, the eflect being to change the fuel-speed characteristic of the governor when a given engine speed is attained.

It is usual in liquid fuel injection pumps to make a provision whereby on starting the engine, the fuel can be supplied temporarily at a rate in excess of the normal maximum rate, and the object of the present invention is to enable the stops in a pump of the kind above mentioned to be utilized for enabling the desired excess fuel to be provided when starting the engine.

The invention comprises a pump of the kind specified in which multiple stops are provided on one end of a lever and in which a manually operable push piece is provided for moving the said lever to an inoperative position, the arrangement being such that when the lever is moved from its normal position, the governor actuated lever can be moved to a position in which the pump can provide the desired extra fuel.

In the accompanying drawings, Figure 1 illustrates diagrammatically a typical embodiment of the invention. Figures 2 and 3 show the position of the stops when extra fuel is required for starting the engine.

Referring to the drawings, the centrifugal governor a on the driving shaft b of the pump (which shaft derives its motion from the engine) is connected to the slidable control bar c of the pump through a lever 11 which is pivoted on another lever e, the latter being angularly adjustable by the driver by a manually operable lever f, to determine the speed at which the governor becomes operative, and the lever f being connected to the lever e through a pair of spring blades g.

On the governor actuated lever are provided at least two lateral projections h, three being provided in the example illustrated, one of which is situated at the free extremity of the lever and the other or others at such positions as those shown.

Adjacent to these projections there is pivoted in the T-shaped lever i on the head of which are provided stops i corresponding to the projections h on the lever d. When the outer end of the lever f is moved downwardly through a given distance from the position shown, which is the idling position, the efiect is to cause the control bar to be moved through the medium of the levers e, d in the direction for increasing the fuel supply until the upper projection h on the lever d comes into contact with the upper step i on the lever i. As the upper stop 1' now 2,839,287 Patented June 17, 1958 prevents further movement of the lever e in the same direction by the lever f, it follows that further downward movement of the outer end of the latter lever causes the upper spring blade 3 to be deflected upwardly, but as the engine speed increases (as a result of the above mentioned movement of the control bar c) the lower end of the lever d is moved to the right by the centrifugal mechanism a to effect further movement of the control bar in the direction for increasing the fuel supply until the upper spring blade g is permitted, by the accompanying movement of the lever e, to re-assume its its normal undeflected condition. Further movement of the lever e in the same direction by the governor a is now opposed by the lower spring blade g, and further increase of speed will cause the lever d to be moved, about its pivotal connection with the lever e, in the direction for causing the control bar 0 to reduce the fuel supply. If now the lever f is moved still further from the idling position, the above described action is repeated and the condition is reached in which the second projection h is brought into contact with the second stop before the spring blade g resumes its normal position. Meanwhile the upper projection h and stop 1' will have separated. A still further movement of the lever f will in like manner bring the third projection h into contact with the third stop i. The mode of determining the various supply positions of the control bar by the interaction of a plurality of stops as above described, is however, known and forms no part of the present invention, the latter being concerned only with the means provided for giving extra fuel when starting the engine.

On the housing is mounted a push piece k which is manually operable and by which the lever i can be moved to the position shown in Figure 2 to enable the governoractuated lever d to move the control bar c to a position in which the pump can supply the extra fuel required when starting the engine as shown in Figure 3. The push piece I: and lever i may be returnable to the normal position by a spring on release of the push piece, but preferably the arrangement shown in the drawings is employed. in this arrangement the push piece It acts on an intermediate catch piece m contained in a housing 0, the catch piece being loaded, and is tiltable, by a spring n. On the catch piece is formed a circumferential groove, and the inner end of this piece extends through a non-axial hole in the said housing. Normally the catch piece occupies the position shown in Figure I. On depressing the push piece It, the spring causes the catch piece to assume a position co-axial with the push piece and so causes the grooved part of the catch piece to engage and be held by the edge of the hole p as shown in Figure 2. On movement of the lever d by the lever f to the position shown in Figure 3, the upper projection h strikes the catch piece and disengages it from the hole p, so allowing the catch piece and push piece to be returned to their initial position by the spring n, the lever i being meanwhile held by the lever d. When the lever 11 is moved away from the lever i the latter can return to it normal position under the action of spring q.

On the pivot of the lever i may be mounted a manually operable lever r to which the spring q is attached, which lever abutment against a shoulder s on the control bar 0 can be used by the driver for moving the control bar in the direction for reducing the fuel supply and thereby bringing the engine to rest.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

Means for controlling a fuel injection pump for an internal combustion engine, comprising in combination a slid-able control bar for varying the output of the pump, a centrifugal governor adapted to be driven by the engine. a first lever through which said control bar is connected to said governor, a second and manually operable lever on which said first lever is pivoted, and which serves to determine the speed 'ar'which said governor becomes operative, at least two projections on said first lever, at least two stops with which said projections eo-operate respectively for limiting the fuelincreas- 5 ingmovements that can be imparted to said control her by said first lever in response to successive movements of said second lever, a third lever on one end of which said stops are provided, a manually'operable push piece, a 891,282 spring-loaded catch piece through the medium of which 10 lQZiER-i said third lever is'movable by said push piece into 21 2.117.248 position in which said stops are ineffective, and retaining 1.556,774

References Cited in the file of this patent UNITED STATES PATENTS means for engaging said catch piece to retain it in the depressed position towhich it is movable by said push piece, said catch piece being releasable from said retaining means by the first lever.

McHugh June 23, W08 Gardner et al. s- Sept. 5, 1933 Hurst et a1. May 10, 1938 Nicolls June 12, 1951 

